The present invention relates to the field of optical fiber technology. It relates to an optical connector for detachable connection of a circuitboard (xe2x80x9cboardxe2x80x9d) to a mounting rear wall (xe2x80x9cbackplanexe2x80x9d) according to the definition of the species of claim 1.
Such a connector is known from German Patent 196 19 374 C1, for example.
When combining individual circuitboards (xe2x80x9cboardsxe2x80x9d) to form an overall system in which the boards are designed to be individually pluggable and are interconnected functionally by plugging them into a mounting rear wall (xe2x80x9cbackplanexe2x80x9d) or they may be connected functionally to signal inputs or outputs, there is also a growing demand for fiber optic plug-and-socket connections and connectors for optical fibers by means of which not only electric signals but also optical signals can be exchanged between the individual boards and the backplane. Since defined pressing forces of the abutting fiber end faces must be maintained with such a fiber optic plug-and-socket connection, comparatively high occur, in particular when a plurality of individual fiber optic connections must be established per board with the connector at the same time; unless special measures are taken, these forces can act on the backplane, causing deformation which then makes individual connections unserviceable. In addition, it is important to be able to compensate for the changes in length which necessarily occur when a plurality of plugs are used per board. At the same time, however, measures must be taken to ensure that the connection is secured to prevent the plug and socket from coming apart after being connected.
European Patent 430,107 B1, in particular FIGS. 3(a) through 3(j) there and the respective parts of the description, has already proposed a fiber optic connector, where an inner housing 36 on the socket end is mounted in an outer housing 34 so it is displaceable in the direction of plug insertion. When fully inserted, the inner housing is prevented from moving relative to the outer housing by a first locking mechanism in the form of a first snap clip or a catch tongue 38 and a first catch step 37. An unlocking element 41 provided on the plug end unlocks the first locking mechanism when the plug is inserted into the socket, thus ensuring free displaceability of the plug-and-socket connection inside the outer housing after insertion. The first locking mechanism and the respective unlocking element are accommodated at the side, namely on one side of the connector.
A second locking mechanism comprising a second snap clip 40 arranged on the plug and a respective second catch step 39 arranged on the inner housing causes the plug to be engaged and locked with the inner housing when inserted into the socket and permits it to move together with the inner housing relative to the outer housing in the direction of plug insertion. The second locking mechanism is also arranged at the side, but on the other side of the connector. In this case, the plug is fixedly connected to the backplane while the outer housing of the socket part is fixedly mounted on the board.
However, there are various disadvantages to the two locking mechanisms arranged at the side, acting independently of one another. For a proper plug insertion process, it is important for the two locking mechanisms to be operated (locked or unlocked) in a certain sequence, as illustrated in detail in FIGS. 3(a) through 3(j) of the aforementioned publication. However, since the two locking mechanisms are arranged on opposite sides of the connector and function independently of one another, there is the danger that the proper operating sequence might not be guaranteed any longer in insertion due to skewing of the plug.
However, the bilateral arrangement of the locking mechanisms is especially unfavorable with respect to flexible modular use of the connector with a freely selectable number of individual fiber optic connections, because lateral expandability in a fixed, predetermined grid spacing is impossible. German Patent 196 19 374 C1, the document mentioned above, also disclosed a plug-and-socket connection for optical fibers arranged together with electric plug-and-socket connections on a circuitboard which can be inserted into a frame, where the tolerances predetermined by the electric plug-and-socket connections are compensated by the fact that the half of the plug-and-socket connection for optical fibers arranged in the frame has a plug part which is held and locked in a carrying body. This lock is released when the halves of the plug-and-socket connection are joined, and instead a locking engagement is formed with the second half of the plug-and-socket connection of the circuitboard, so the plug part is held displaceably in the carrying body due to the fact that the locking engagement with the carrying body is released.
The detachable engagement is accomplished here by an interaction between two spring arms 9 that are integrally molded in one piece on the plug part, their front ends being provided with inclined faces and catch shoulders, and two (rigid) catch arms 28 integrally molded on a mounting part secured on the circuitboard. However, such an engagement and disengagement mechanism requires a complicated movement operation in insertion and accordingly a complex design in terms of the geometry and arrangement of the individual catch elements.
Therefore, the object of this invention is to create an optical connector which avoids the disadvantages of the known connector and ensures synchronized operation of the locking mechanisms, especially with a compact design, and permits a flexible modular manufacturing design with regard to the individual fiber connections.
This object is achieved through the totality of features of claim 1. The core of this invention consists of the fact that the first locking means comprise a first snap clip provided on the inner housing, extending in the direction of plug insertion, and in the locked state it snaps behind a first locking shoulder arranged on the outer housing; the socket comprises an outer housing and an inner housing, where said inner housing is mounted displaceably in the direction of plug insertion and is secured to prevent displacement within the outer housing by means of the first locking means; the minimum of one plug comprises a body having a plug-in part; the second locking means comprise a second snap clip which is mounted on the body and extends in the direction of plug insertion, and in the locked state, it snaps behind a second locking shoulder arranged on the inner housing of the socket; and the two snap clips are designed and arranged so that the second snap clip snaps first behind the second locking shoulder on insertion of the plug, and then the first snap clip is lifted above the first locking shoulder and is thereby unlocked.
The solution according to this invention is characterized by a simple design and reliable functioning and can be manufactured advantageously with the means of the injection molding technology. The second locking means which are provided for mutual locking of the plug and socket are also used at the same time for unlocking the first locking means which lock the inner housing in the outer housing in the case of the socket. In this way, a forced synchronization of the two locking and unlocking operations is achieved. At the same time, both of the locking mechanisms can be accommodated compactly on the same side; so that the opposite side is freely accessible and is not subject to any restrictions. It is selfevident that the inner housing can be designed to be displaceable in the outer housing in the case of either the bushing or the plug without any change in effect.
It is especially advantageous if according to a first preferred embodiment of this invention, the first and second locking means are arranged on the side of the connector facing the circuitboard or facing away from it. This does not result in any restrictions laterally on either side of the connector with regard to a space-saving alignment of a plurality of connectors in a row side by side. In addition, in this way, the locking means can be brought very close to the longitudinal axis of the connector, so that the pressing forces originating from the ends of the optical fibers, acting on the longitudinal axis, yield a very small locking moment which does not cause any wedging.